In an annual ring, the light coloured part is known as
1 autumn wood
2 late wood
3 heart wood
4 sap wood

Options

A. autumn wood
B. late wood
C. heart wood
D. sap wood

Answer

To answer the question "In an annual ring, the light coloured part is known as," we need to analyze the options provided and understand the structure of annual rings in trees.

### Step-by-Step Solution:

1. **Understanding Annual Rings**: Annual rings are formed in the secondary xylem (wood) of trees and consist of two parts: the light-colored part and the dark-colored part.

2. **Identifying the Parts**:
- The **light-colored part** of the annual ring is known as **sapwood**. This part is composed of living cells and is responsible for the conduction of water and nutrients.
- The **dark-colored part** is known as **heartwood**, which consists of dead cells and provides structural support to the tree.

3. **Analyzing the Options**:
- **Option 1: Autumn wood** - This refers to wood formed during the late growing season and is not the light-colored part.
- **Option 2: Late wood** - Similar to autumn wood, this is formed when cambium activity decreases and is characterized by narrower vessels, thus it is also not the light-colored part.
- **Option 3: Heartwood** - This is the inner, darker part of the wood, which is not the answer.
- **Option 4: Sapwood** - This is the correct answer as it refers to the light-colored part of the annual ring.

4. **Conclusion**: Based on the analysis, the light-colored part of an annual ring is known as **sapwood**.

### Final Answer:
The light colored part in an annual ring is known as **4. sap wood**.